Gas Valves & Filters

A typical station has isolation ball valves at the inlet and outlet, a gas filter ahead of the regulators, a slam shut valve on each regulating line, a relief valve downstream and, where needed, a bypass valve such as the VLM. Pietro Fiorentini makes each of these, together with the gas pressure regulators and meters, so one supplier can cover the main station components.

A slam shut valve stops the gas flow completely when the monitored pressure passes its set limit. Pietro Fiorentini slam shut valves trip within one second and are reset by hand once the cause is found. A relief valve stays in service and vents a small quantity of gas to limit short pressure rises, for example thermal expansion when there is no flow. Most stations use both.

Choose by pressure. Up to 10 bar, the Filters for Low Pressure range uses 5 micron cloth cartridges (Mod. 50000) or 50 micron elements (Mod. 10000, 106-106/F). For high and medium pressure up to 100 bar, the HFA-HFB dry gas filter uses a 5 micron cartridge with 98% filtering efficiency, a bottom drain and an optional differential pressure clogging indicator.

Yes. The BF 31 and BF 32 are designed for natural gas and previously filtered non-corrosive gases in medium and low pressure distribution networks. They work at up to 16 bar with PN 16 flanges or 19 bar with ANSI 150 RF flanges. The butterfly can rotate 360 degrees, which cleans the seat without removing the valve from the pipe.

A self-operated gas pressure regulator uses the line pressure itself to hold its set point. A control valve such as the Reflux 919 moves on an external signal: pneumatic (0.21 to 1.03 bar or 0.42 to 2.06 bar) or 4-20 mA through an electro-pneumatic positioner. This lets a station controller set pressure or flow. For self-operated regulation, see our gas pressure regulators.